Machinist s calculator



Dec. 25,1945; 5 HAvlLANg 2,391,570

MACHINIST S CALCULATOR Filed March 20, 1943 3 Sheets-Sheet l PatentedDec. 25, 1945 UNITED STATES PATENT OFFICE MACHINISTS CALCULATOR Earl H.Haviland, Baltimore, Md.

Application March 20, 1943,, Serial No. 479,849

2 Claims.

This invention appertains to machinists tools and more particularly to adevice for giving readings in a facilitated form. It is particularlyintended for use in the setting, or use of equipment in the productionof mechanisms. The objects of this invention include the provision of aportable instrument able to be manipulated easily to bring various linesof information or data to the attention of the user, as needed toperform Various functions or processes in machine or tool work. Also topresent in a mechanical manner such information customarily andconventionally printed in books or loose charts, that are hard to employwhile the worker is doing his Work on a machine or bench. Another objectis to do. certain operations of addition and subtraction of inches orparts of inches or' other common scales in quick. simple andinterpolated manner. Afurther object is to provide a device that canwithstand hard use in the shop; that will keep its informationconveniently available and accessible under difficult conditions withoutdifiicult compilations, and which will not become damaged and unusablethrough ordinary use, such as by oil, dirt and dropping, A still furtherobject is to have the device non-rolling and self indicating.

Other objects will become apparent as the invention is more fully setforth.

In the us of machines and tools b machinsts and toolmakers, the sizes ofdrills, taps, the proper index plate to be used on the head of a millingmachine, the cords of various circles, the amount of taper per footincluding the angle thereof, division and multiplication of decimals andother items are frequently necessary. Th obtaining of such informationbecomes a matter of investigation through books. or charts, assumingthat they are available, aside from the great loss. of time. The oilyand dirty condition of the equipment, causesv the books and charts tobecome soiled and damaged in. a very short time. This formerarrangementis also cumbersome and invites mistakes; In this invention,the use of books or loose charts is eliminated. The device is providedwith the data arranged on a cylinder in straight lines, easily followedunder eye holes provided in its cover.,- The parts are preferably madeof a common plastic and are cleana'ble. The printing necessary forproviding the information can be readily printed or impressed on thismaterial, so as to show up clearly. Mechanism provided atone endprovides a simple but effective way of deriving fractions and decimalsand add ing or subtracting therefrom, as well as giving audible signalsof the value of the answer.

In the drawings which illustrate an example of this invention:

Figure l is a plan view of a machinists calculator embodying thisinvention;

Figure 2 is a side elevation partly in section to show the operatingmechanism;

Figure 3 is an end View of Figurel;

Figure 4 is an end view of the rotating end of thedevice shown in Figure1;

Figure. 5 isa view taken along lines 5-5 of Figure 2 with the bolt49removed;

Figure. 6 is. a view taken along lines 6-6 of Figure 2;

Figure 7 is a view of the chart used in this device;

Figure 8 is a dismantled view of the operatmg. end portionin'perspective looking at their rear or internal faces, the parts beingseparated to make their construction clear;

Figure 9 is another view of the same parts indicated in Figure 8 lookingat their 'front faces, in perspective;

Figure 10- is a perspective view of the cylinder body of the device;

Figure 11 is a perspective view of the cover used over the cylinderbody, and

Figure 12 is an enlarged view of rotating end of the device partly insection.

Similar reference characters refer to similar partsthroughout thedrawings.

In the drawings, I represents a cylinder consisting of a body havingraised spaced ridges 2 to separate its external and peripheral surfaceinto sections, 3 and 4. Its end portion 6 is formed into a hexagoncontour l to give it a nonrolling feature, when laid, down on ahorizontal surface. The opposite end portion 8-known as the adding,subtracting and decimal and fraction conversion end is centrallyrecessed and tapped at 9 to receive a bolt having screw threads 5. Apawl. ID is supported in a slot II in the same portion 8 and acts on itshinge pin 12 to rotate in the longitudinal direction of the device. Thispawl is. preferably constructed as indicated in the drawings with itsengagement piece l3 formed with flattened sides l4 and beveled edges 15.The lower portion is extended at 16 to function in the manner to bedescribed, and the hole I! takes the hinge pin 12. The recess H3 in theportion 8 is made to align the cylinder and adjacent index sleeve shield24 that fits into it.

A revolving mechanism is mounted on the fraction adding and subtractingand. decimal conversion end' B with the peripheral surface of its.barrel registered with the peiipheral' surface 20 of surface for same.

the cylinder end 8. The surface I9 adjacent of a flange end 29 isengraved with marks 2| used for adding or subtracting purposes. Themechanism consists of several main parts, namely the handle piece 22;the cylindrical escapement drum 23 with its notches 21; the index shield24; the clicking washer 25 and tripper 26; a sleeve 36 and a bolt 49having the screw threaded end portion adapted to engage in the screwthread 9 and coil spring 23 for tensioning the sleeve. The washer 25 ispress fitted to the end of the sleeve 36 to prevent its moving.

The handle piece 22 has an outer rim 29 extended to align with thehexagon I of the opposite end of the roll. It is dished at 3| and theplate 32 forming its bottom is arcuately slotted at 33 to permitinspection of the back 36 of the escapement drum 23 through a hole 38 inthe shield 24 that is positioned between it and the back of theescapement drum. This escapement drum 23 has figures 34 engraved on itand adapted to show through the slot 33 and hole 39 when properlyregistered therewith. The escapement drum 23 is held and guidedperipherally by the circular inside surface 39 that surrounds it.Internally and centrally the shield 24 is provided with a cylindricalboss 46 having a central hole 46 through it. This boss fits closelywithin a centrally located recess 42 in the back portion of theescapement drum 23 and serves to keep it in place and provide a bearingThe front portion of the escapement drum is recessed centrally at 43 toreceive and hold the clicking washer 25. The sleeve 36 is as indicatedin Figures 8 and 9 having a cylindrical pipe like portion, on which acylindrical head 47 of larger external diameter is mounted at one end.This head is counter sunk to permit the head 59 of the bolt 49 to set inflush, while the body of the latter passes through inside the sleevewith its screw threaded portion 5 projecting out, and disposed in thethreaded hole 9. Externally the sleeve surface contacts with theinternal surface of three parts. The internal surface of the centralholes 44 of the handle piece 22; the internal surface of the hole 46 inthe boss 46, and the hole 44 in the cylindrical escapement drum member23, to act as a support for washer25, and aligns them all with eachother. of the sleeve 36 presses against the spring 26 which contacts theface of the plate 32, when in place. The passage 48 through the sleeveallows the holding element 49 to pass through it and thread into screwthreads 9, while its head 56 sets in a counterbore recess 5! in thesleeve head 41. The bolt is counterboredcentrally at 53 to receive awrench used for screwing it in. The washer 25 has a bevelled trip pinridge 26 on its face 54 large enough to strike and operate the extendedportion I 6 of the pawl. When the ridge 26 contacts the portion I6itmoves the pawl l3 into contact with the notch 21 of the escapement drum23 so the latter cannot be turned with the sleeve and piece 22 for thespace of onetooth and show the proper numeral 34 through hole 38 andarcuate slot 33. The coil spring 28 is disposed between the head 41 ofthe sleeve 36 and the face 32 of the barrel piece 22 to give the formerfrictional and resilient resistance.

The sections of the cylinder have light colored plastic charts 55closely attached to the circumferential surfaces of same. The charts arepreferably printed in columns A, B C, D, E, F,

The knurled enlarged head 4! G, H, with data pertaining to drills, taps,decimals, fractions, chords, number of screw threads and otherinformation. A cover 56 preferably of plastic is mounted over thecylinder as shown, and between the hexagon and handle.

This cover has its end edges 51 serrated to engage in serrations 58 onthe cylinder edges. This is to control the movement of the cover thereonand prevent its slipping. The ridges 2 raise the cover off the printedforms or cards 55, and keep it from rubbing off the printing orimpressed marks therefrom. Openings 60 in the cover form eye holes foreach double or single column and are aligned horizontally across topermit all in a line to be read 01f at one reading, if desired. Thetitles 59 of each column are marked off on the cover to identify sameeasily.

The pawl however holds the notch and prevents the escapement drum fromrotating while the tripper 26 rotates through the space of one notch.The spring 6| rocks the pawl ll) out of engagement with the notchas'soon as the lug 26 rotates past the pawl and'thereby releases it andallows the escapement drum 23 to rotate with the sleeve 36. The pawl isthen dropped back into the notch following and holds the escapement drumuntil the sleeve and the parts operating therewith have moved aroundanother revolution. This action is then repeated. There is sufficientfriction between the sleeve and the escapement drum to permit this, whenthe pawl is not engaged and holding it stationary. The serrations holdsthe cover and barrel together, even when a little force is applied andpermits one to ride on the other. This is to prevent slipping and notobstruct the turning of the cover on the barrel.

The markings of the card are preferably arranged in vertical columnswith their quantities aligned on horizontal or transverse lines acrossthe card, as indicated; The columns are listed or titled somewhat asfollows:

A (Taps and tap drills).

B (Milling index).

C (Cord of 1" circle). v

D (Taper per foot including the angle).

E (Drill number).

F (Division of decimals).

G (Multiple decimal).

The readings are made to suit those common quantities frequently broughtinto use in the machine or tool shop. The horizontal figures followseach other in sequence to bring out different values, preferably relatedin some way to each other. This is brought out by referring to the listof numerals shown on the drawings as a separate figure.

The items on the charts are read by adjusting the cover on the cylinderuntil the inspection openings 69 are aligned with the line of horizontalfigures selected to be read. They are read easily without confusion withthose on other lines. This makes the process of getting the valuesquicker and more accurate. The last column 62 on the chart or card isarranged to rotate and is for a different purpose and is on the part 24.It has a series of fractions 63 and corresponding decimals 64 verticallyarranged as shown. Next to the rotating card 62 is a fixed card 65attached to the section 4 comprising a series of fractions 66 anddecimals 67 which are similar to those shown on card 62. On theperipheral surface H! of the index shield is marked a series of markingssimilar to the markings found on the sleeve and barrel of a micrometerand are added or subtracted in the same way, and are arranged to add upwith the series 62 and 63 above mentioned.

The card having the column 62 marked thereon is secured to the element24 in any suitable manner, so as to turn with it. The turning of theknob 4'! does this directly. Attached to the knob is a sleeve whichrotates the element 2d. The gear 23 is rotated by the sleeve through itsfrictional contact through the boss 40, and wick H. The column 65 issecured to the body I, and is to be considered as stationary with it.

The operation of the device is as follows:

Turn the outer rim 29 until the zero on the peripheral surface IQ of thebarrel 22 aligns with the mark 1.000, on the card 62 and zero (0) on theback of the escapement drum gear 23 shows through hole 38 and arcuateslot 33. The device is now ready for use. Assume that the dimentions 1",/5, and 1% are to be added together, the procedure will be as follows:Turn the knurled head 41 one full turn until the number one (1), showsthrough hole 38 and slot 33 and a click is heard. The head 4'1 is thenturned until the markings 1.000, on card 82 is aligned with the fractionand corresponding decimal on card 65. (The zero 0 on the peripheralsurface I?) of the barrel 22 should still be aligned with the mark 1.000on the card 62.) With this setting the user of the device glances up thecolumn of figures on the card 62 until he reaches the fraction 1%".Opposite this he will find the total of the fraction to be which plusthe one inch (1") will be showing through the hole 38 and slot 33,making a total of h s".

If the user wishes to subtract a fraction or decimal he proceeds asfollows: Take as an example 11 g" minus se". The setting will remain thesame as above and the operator will find 2" on the card 62 to beopposite is" on card 65. The answer is 133 or 1.40625. By this method afrac tion or decimal can be added or subtracted from each other. In theevent it is desired to subtract g" from 1 the procedure will be asfollows: Align the 1%" mark on the card 62 with the 1 6" mark on thecard 65, glance down card 62 until you reach the mark 1.000, andopposite you will find the answer to be When the addition rises aboveunity, then the tripper 2B of the washer 25 will come into contact withthe lower portion l6 of the ratchet pawl iii and forces the engagementpiece l3 between the notch 21. This holds the escapement drum fixed tothe cylinder and allows the hole 38 and slot 33 to slip over theescapement drum until a new member shows up in the slot and hole. Thelower portion l6 of pawl l0 contacts the face 54 of the washer 25through the operation of spring Bi and withdraws the engagement piece l3from contact with the notch and allows the escapement drum to rotatefree of the fixed cylinder until a complete revolution has been made.You can reverse the operation and subtract whole numbers.

If the fractions add up to two inches 2" plus a fraction or decimal, theback of the escapement drum will show (2) through the hole 38 and slot33 in the same manner. The bolt 49 and its incidental parts will fastenin place as indicated in the drawings. The escapement drum is givenadjustable frictional resistance by the screw '10 and frictional insertH as it presses on the circumferential surface of the sleeve 35. Thescrew 10 is operated from the periphery of the escapement drum 23 andindex shield 24 by inserting a screw driver in the counterbored hole 72in the escapement drum and hole 13 in the index shield.

While but one general form of the invention is shown in the drawings anddescribed in the specifications, it is not desired to limit thisapplication to thi particular form or in any other way otherwise thanlimited by the scope thereof, as it is appreciated that other formscould be made that would use the same principles and come within thescope of the appended claims.

Having thus described the invention what is claimed is:

1. In combination, a body, a revolving mechanism associated therewithcomprising, a barrel piece with an enlarged flanged end for manualoperation thereof, an index shield disposed against the said barrelpiece, a toothed drum rotatably mounted in the shield normally rotatabletherewith, said drum having indicia thereon for dis play through anaperture in the shield, means for holding said element against the bodyand rotatably supporting them, a pawl mounted in the body normally freeof the toothed drum and adapted when actuated to lock the toothed drummomentarily against rotation, means to actuate the pawl once for eachrevolution of the index shield, means in the barrel piece for displayinga given value on the toothed drum which has been positioned at theaperture in the index shield, the rotation of the elements beingcorrelated with a second set of indicia on the index shield, a set ofindicia on the body and markings on the barrel piece.

2. In combination with the body of a device of the class described, arevolvable mechanism comprising in combination, a bolt secured to thebody and extending axially therefrom, a sleeve mounted on the bolt androtatable thereon, a cam fastened to an end of the sleeve adjacent thebody, a toothed drum rotatably mounted on the sleeve, a pawl. mounted inthe body normally free of the toothed drum and adapted to be actuated bythe cam once for each revolution of the latter to cause the pawl tomomentarily engage the toothed drum and lock it against rotation "whileso en gaged, indicia on the outer face of the toothed I A drum, an indexshield having a cylindrical surface with indicia thereon rotatablymounted on the sleeve and having a display aperture in its end fordisplay of a selected value on the toothed drum, a barrel piecerotatably mounted on the sleeve and provided with an end flange formanual operation thereof and having an extended aperture in its end forallowing the aperture in the index shield to be displayed therein, aspring mounted on the sleeve between the barrel piece and a head on theouter end of the sleeve, indicia on the cylindrical surface of the bodyand index shield, respectively, the indicia on all the elements being socorrelated that the fractional portion of a sum, in addition, will bedisplayed on the body and the whole portion on the toothed drum,

which whole portion will be displayed through the ahgned displayapertures in the index shield and barrel piece.

EARL H. HAVILAND.

